1. Field of the Invention
The present invention relates to an individual package, in which an absorbent article, such as sanitary napkin, panty liner, sanitary tampon, incontinence pad, disposable diaper and so forth is individually packed.
2. Description of the Related Art
For example, an absorbent article, such as sanitary napkin or the like, is individually packed into an individual package. Conventionally, a package sheet of the individual package is formed from a polyethylene film or the like. It is a typical structure that side portions of the package sheet are heat sealed in a condition wrapping the absorbent article.
However, the package sheet formed from a resin film, such as polyethylene film and so forth may generate husky (or crinkly) noise upon handling due to friction with a packaging film upon opening the package and taking out the absorbent article. This is true even in the case where the individual package is taken out from a porch, is carried in hand, or is carried in a pocket of pants or skirt. On the other hand, the resin films are firmly bonded by heat seal to cause difficulty in opening the package for large anti-peeling resistance upon peeling the heat sealed portion. Furthermore, since the large force is required in opening the package, high husky or crinkly noise can be generated. As a result, uncomfortable feeling may be caused for the fear if unpacking of the sanitary napkin or the like can be perceived by surrounding people. On the other hand, the package sheet formed from polyethylene film is not always preferably in terms of product form due to stiff external appearance of the individual package. Furthermore, since the polyethylene film is heat sealed, gas-tightness of the sealed individual package becomes excessively high to cause bursting of the package sheet at the heat sealed portion when large external force is applied during carrying.
In view of the inconvenience set forth above, there have been proposed individual packages having the package sheets formed from non-woven fabric, such as those disclosed in Japanese Unexamined Patent Publication (Kokai) No. Heisei 11-42248, for example. In case of individual package of the absorbent article employing the package sheet of non-woven fabric, husky noise to be generated by such package sheet upon unpacking is small. Furthermore, since bonding area of the heat sealed portion is substantially small, peeling sound upon unpacking the heat sealed portion becomes small. Also, the non-woven fabric package sheet may provide soft external appearance for the individual package to attain better appearance. Furthermore, when large external force is applied, air in the individual package may escape through gaps between fibers of the non-woven fabric so as not to cause bursting during carrying.
In the individual package, it is typical that a base end portion of a tape is fixed on a surface of the package sheet portion located at the outermost position in the condition where the end edges of the package sheet are overlapped on an outer surface of the package sheet, and a free end of the tape is extended beyond the end edge of the package sheet and is peelably bonded on the surface of the package sheet adjacent to the end edge. Upon unpacking of the individual package of the absorbent article, the free end of the tape is peeled from the surface of the package sheet adjacent to the end edge, and the package sheet on which the base end of the tape is fixed is lifted up together with the tape, thereby the heat sealed portion can be peeled to easily unpack the individual package.
However, in the package sheet formed from the non-woven fabric, fibers appear on the outer surface in random fashion. Therefore, in a fixing portion between the fibers on the surface of the package sheet and the base end of the tape, bonding area becomes substantially small to lower fixing strength. Therefore, when the free end of the tape is peeled from the surface of the package sheet adjacent to the end edge and lifted up, the base end of the tape can be easily peeled from the surface of the package sheet. Accordingly, once the entire tape is peeled and removed, inconvenience is encountered in handling upon unpacking the individual package.
On the other hand, in case of the individual package of the sanitary napkin, upon wearing the unpacked sanitary napkin, the unpacked package sheet may be used for wrapping the used sanitary napkin. Then, the free end of the tape extending from the end edge of the package sheet is bonded on the outer surface of the package sheet for disposal. However, if the base end of the tape is not firmly fixed on the package sheet, when the free end of the tape is pulled for firmly wrapping the used sanitary napkin by the package sheet, the base end may be peeled off the outer surface of the package sheet to cause difficulty in wrapping the used sanitary napkin for disposal.
In order to solve the problem set forth above, an approach is considered to use an adhesive having high bonding strength in fixing the base end of the tape on the surface of the package sheet, and to use an adhesive having lower bonding strength in bonding the free end of the tape on the surface of the package sheet at the position adjacent to the end edge of the package sheet. In another approach, greater thickness may be provided for the adhesive at the portion where the base end of the tape is bonded on the surface of the package sheet, and smaller thickness may be provided for the adhesive at the portion where the free end of the tape is bonded on the surface of the package sheet. However, using two kinds of adhesives in bonding the tape on the package sheet or varying application amounts at different positions inherently make packaging process complicate to increase manufacturing cost. Furthermore, the adhesive used for fixing the base end of the tape may run out toward the position of the package sheet on which the free end of the tape is bonded, to fix the free end of the tape with excessively large bonding strength on the package sheet to cause difficulty in unpacking.